The Nationals' new deputy leader, Fiona Nash, will be promoted to cabinet, increasing the number of women to six.

The reshuffle follows the departure of Human Services Minister Stuart Robert, who resigned over a China trip with a Liberal party donor, and Cities Minister Jamie Briggs, who resigned over a Hong Kong bar scandal.

Special Minister of State Mal Brough has been suspended from his job pending a federal police investigation into the copying of former speaker Peter Slipper's official diaries.